Selective breeding may result in a greyhound running faster and seeing better than a wolf.

However, serum collected from racing Greyhounds between 1984 and 2004 and tested for canine influenza virus (CIV) in 2007 had positive tests going as far back as 1999.

The highly contagious equine influenza virus H3N8 was found to have been the cause of Greyhound race dog fatalities from a respiratory illness at a Florida racetrack in January 2004.